com32/mboot/mb_header.h

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2000   Free Software Foundation, Inc.
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #ifndef MBOOT_MB_HEADER_H
  21 #define MBOOT_MB_HEADER_H
  22
  23 #include <inttypes.h>
  24
  25 /*
  26  *  MultiBoot Header description
  27  */
  28
  29 struct multiboot_header {
  30     /* Must be MULTIBOOT_MAGIC - see below.  */
  31     uint32_t magic;
  32
  33     /* Feature flags - see below.  */
  34     uint32_t flags;
  35
  36     /*
  37      * Checksum
  38      *
  39      * The above fields plus this one must equal 0 mod 2^32.
  40      */
  41     uint32_t checksum;
  42
  43     /* These are only valid if MULTIBOOT_AOUT_KLUDGE is set.  */
  44     uint32_t header_addr;
  45     uint32_t load_addr;
  46     uint32_t load_end_addr;
  47     uint32_t bss_end_addr;
  48     uint32_t entry_addr;
  49
  50     /* These are only valid if MULTIBOOT_VIDEO_MODE is set.  */
  51     uint32_t mode_type;
  52     uint32_t width;
  53     uint32_t height;
  54     uint32_t depth;
  55 };
  56
  57 /*
  58  * The entire multiboot_header must be contained
  59  * within the first MULTIBOOT_SEARCH bytes of the kernel image.
  60  */
  61 #define MULTIBOOT_SEARCH                8192
  62
  63 /* Magic value identifying the multiboot_header.  */
  64 #define MULTIBOOT_MAGIC                 0x1BADB002
  65
  66 /*
  67  * Features flags for 'flags'.
  68  * If a boot loader sees a flag in MULTIBOOT_MUSTKNOW set
  69  * and it doesn't understand it, it must fail.
  70  */
  71 #define MULTIBOOT_MUSTKNOW              0x0000FFFF
  72
  73 /* currently unsupported flags...  this is a kind of version number.  */
  74 #define MULTIBOOT_UNSUPPORTED           0x0000FFF8
  75
  76 /* Align all boot modules on i386 page (4KB) boundaries.  */
  77 #define MULTIBOOT_PAGE_ALIGN            0x00000001
  78
  79 /* Must pass memory information to OS.  */
  80 #define MULTIBOOT_MEMORY_INFO           0x00000002
  81
  82 /* Must pass video information to OS.  */
  83 #define MULTIBOOT_VIDEO_MODE            0x00000004
  84
  85 /* This flag indicates the use of the address fields in the header.  */
  86 #define MULTIBOOT_AOUT_KLUDGE           0x00010000
  87
  88 #endif /* MBOOT_MB_HEADER_H */